①If you backtrack on a statement or decision you have made, you do or say something that shows that you no longer agree with it or support it.【v.改变（说法、决定等）；出尔反尔】
②If you backtrack, you go back along a path or route you have just used.【v.原路返回】
③If you backtrack in an account or explanation, you talk about things which happened before the ones you were previously talking about.【v.倒回（描述或解释内容）】
①The finance minister backtracked on his decision.
②We had to backtrack to the corner and cross the street.
③Can we just backtrack a little bit and look at your primary and secondary education?
Matt Haig的新书 The Midnight Library 也出现了这个表达：
throw a curveball
A person who threw a curve ball did something unexpected.
When life throws you a curveball, you need to know how to handle it.
《卫报》一篇题为 Stuck in the middle with the love 的文章也提到了这个表达：